Disposable, flexible plastic or glass fluid dispensers are currently used to dispense all sorts of liquid, or liquid-like, substances. For example, take-out food restaurants offer ketchup and mustard to their customers in disposable plastic dispensers which resemble rectangular pouches, and cosmetic manufacturers offer their customers one-application samples of various products such as shampoo, moisturizer, etc., in disposable plastic or glass flexible dispensers. Similarly, pharmaceutical companies distribute medications, such as liquid vitamins or ointments, in disposable one-dosage dispensers.
The user opens the dispensers by splitting, cutting or puncturing them. Depending on the design of the dispenser, the user may open it by cutting or ripping off a particular section of it, typically along a perforation, puncturing it with a sharp object, or squeezing it until it pops open. Often, when a user rips the dispenser along a perforation, he or she simply pulls off a section of the dispenser without opening it. The user then must squeeze the dispenser to further split it, all the while hoping that the contents of the dispenser do not spray out in all directions through the perforations.
A user who attempts to open a dispenser by puncturing it may end up spewing the contents in unpredictable and often uncontrollable directions. For example, a user attempting to puncture a dispenser at a particular spot may inadvertently squeeze the dispenser with enough force to split it at a different, and often unexpected, spot. The contents of the dispenser may then spill out through the split. Many take-out food customers share the experience of inadvertently splitting a ketchup dispenser and spilling the ketchup all over themselves. If, instead of ketchup, the dispenser contains a liquid medication or a reactive chemical, the consequences of spraying the contents may be serious. What is needed is a disposable dispenser which opens at a predictable spot in a predictable manner.
The unpredictable dispensers present users with a second, related problem, namely, the problem of controlling the amount of liquid which emerges from the dispenser once it is opened. For example, when a user squeezes a dispenser to open it, he or she may squeeze with enough force to cause a relatively large amount of fluid to spurt out of the dispenser through the opening. Similarly, once the dispenser is opened, a later squeeze may result in the dispensing of a large amount of the fluid when the person squeezing the dispenser requires only a small amount. What is needed is a dispenser which releases its liquid contents in a controllable manner.